/*
 * (c) Copyright 2009 Hewlett-Packard Development Company, LP
 * All rights reserved.
 * [See end of file]
 */

package com.hp.hpl.jena.clusteredtdb.pgraph;

public class NodeMask {
	long mask;
	long inversemask;
	int masksize;
	static int longlength = 64;
	static int typesize = 8;
	
	public NodeMask(int masksize) {
		//TODO put in a check to make sure the mask size stays small enough.
		
		this.masksize = masksize;
		//this.mask = ((long)(Math.pow(2,masksize)) - 1) << (longlength - masksize - typesize);
		this.mask = ((long)(Math.pow(2,masksize)) - 1);
		this.inversemask = -1 ^ this.mask;
	}

	public long getInverseMask() {
		return inversemask;
	}

	public long getMask() {
		return mask;
	}

	public int getMaskSize() {
		return masksize;
	}
	
	public int getVNodeFromNodeId(long nodeid) {
		//return (int)((nodeid & mask) >>> (longlength-masksize-typesize));
		return (int)(nodeid & mask);
	}
	
	public long createMaskedId(int vnodeid, long i) {
		//long idmask = (long)vnodeid << (longlength-masksize-typesize);
		long idmask = vnodeid;
		return (i << masksize) | idmask;
	}
	
	public long getDiskAddressFromId(long i) {
		return i >>> masksize;
	}
	
}

/*
 * (c) Copyright 2009 Hewlett-Packard Development Company, LP
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
